| 1. |
- Ablikim, M., et al.
(författare)
-
Search for C-parity violation in J/psi -> gamma gamma and gamma phi
- 2014
-
Ingår i: Physical Review D. - 1550-7998 .- 1550-2368. ; 90:9, s. 092002-
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Tidskriftsartikel (refereegranskat)abstract
- Using 1.06 x 10(8) psi(3686) events recorded in e(+)e(-) collisions at root s = 3.686 GeV with the BESIII at the BEPCII collider, we present searches for C-parity violation in J/psi -> gamma gamma and gamma phi decays via psi(3686) -> J/psi pi(+)pi(-). No significant signals are observed in either channel. Upper limits on the branching fractions are set to be B(J/psi -> gamma gamma) < 2.7 x 10(-7) and B(J/psi -> gamma phi) < 1.4 x 10(-6) at the 90% confidence level. The former is one order of magnitude more stringent than the previous upper limit, and the latter represents the first limit on this decay channel.
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| 2. |
- Ablikim, M., et al.
(författare)
-
Amplitude analysis of the D+ -> K-S(0)pi + (0)(pi) Dalitz plot
- 2014
-
Ingår i: Physical Review D. - 1550-7998 .- 1550-2368. ; 89:5, s. 052001-
-
Tidskriftsartikel (refereegranskat)abstract
- We perform an analysis of the D+ -> K-S(0)pi + (0)(pi) Dalitz plot using a data set of 2.92 fb(-1) of e(+) e(-) collisions at the (3770) mass accumulated by the BESIII experiment, in which 166694 candidate events are selected with a background of 15.1%. The Dalitz plot is found to be well represented by a combination of six quasitwo- body decay channels [k(SP)(0)(+) (1450)(+,) ] plus a small nonresonant component. Using the fit fractions from this analysis, partial branching ratios are updated with higher precision than previous measurements.
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| 3. |
- Ablikim, M., et al.
(författare)
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Measurement of chi(cJ) decaying into eta ' K+K-
- 2014
-
Ingår i: Physical Review D. - 1550-7998 .- 1550-2368. ; 89:7, s. 074030-
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Tidskriftsartikel (refereegranskat)abstract
- Using (106.41 +/- 0.86) x 10(6) Psi(3686) events collected with the BESIII detector at BEPCII, we study for the first time the decay chi(cJ) -> eta'K+K- (J = 1, 2), where eta' -> gamma rho(0) and eta' -> eta pi(+)pi(-). A partial wave analysis in the covariant tensor amplitude formalism is performed for the decay chi(c1) -> eta'K+K-. Intermediate processes chi(c1) -> eta'f(2)'(1525) chi(c1) -> K-0*(1430)K-+/-(-/+) (K-0*(1430)(+/-) -> eta'K-+/-) are observed with statistical significances larger than 5 sigma, and their branching fractions are measured.
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| 4. |
- Ablikim, M., et al.
(författare)
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Measurement of the branching fraction for psi(3686) -> omega K+K-
- 2014
-
Ingår i: Physical Review D. - 1550-7998 .- 1550-2368. ; 89:11, s. 112006-
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Tidskriftsartikel (refereegranskat)abstract
- With 1.06 x 10(8) psi(3686) events collected with the BESIII detector, the branching fraction of psi(3686) -> omega K+K- is measured to be (1.54 +/- 0.04 +/- 0.11) x 10(-4). This is the most precise result to date, due to the largest psi(3686) sample, improved signal reconstruction efficiency, good simulation of the detector performance, and a more accurate knowledge of the continuum contribution. Using the branching fraction of J/psi -> omega K+K-, the ratio B(psi(3868) -> K+K-)/B(J/psi -> K+K-) is determined to be (18.4 +/- 3.7)%. This constitutes a significantly improved test of the 12% rule, with the uncertainty now dominated by the J/psi branching fraction.
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| 5. |
- Ablikim, M., et al.
(författare)
-
Observation of e(+)e(-) -> gamma X(3872) at BESIII
- 2014
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Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 112:9, s. 092001-
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Tidskriftsartikel (refereegranskat)abstract
- With data samples collected with the BESIII detector operating at the BEPCII storage ring at center-of-mass energies from 4.009 to 4.420 GeV, the process e(+)e(-) -> gamma X(3872) is observed for the first time with a statistical significance of 6.3 sigma. The measured mass of the X(3872) is (3871.9 +/- 0.7(stat) +/- 0.2(syst)) MeV/c(2), in agreement with previous measurements. Measurements of the product of the cross section sigma[e(+)e(-) -> gamma X(3872)] and the branching fraction B [X(3872) -> pi(+)pi(-)J/psi] at center-of-mass energies 4.009, 4.229, 4.260, and 4.360 GeV are reported. Our measurements are consistent with expectations for the radiative transition process Y(4260) -> gamma X(3872).
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| 6. |
- Ablikim, M., et al.
(författare)
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Observation of eta' -> pi(+) pi(-) pi(+) pi(-) and eta' -> pi(+) pi(-) pi(0) pi(0)
- 2014
-
Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 112:25, s. 251801-
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Tidskriftsartikel (refereegranskat)abstract
- Using a sample of 1.3 x 10(9) J/psi events collected with the BESIII detector, we report the first observation of eta' -> pi(+) pi(-) pi(+) pi(-) and eta' -> pi(+) pi(-) pi(0) pi(0). The measured branching fractions are B(eta' -> pi(+) pi(-) pi(+) pi(-)) = [8.53 +/- 0.69(stat.) +/- 0.64(syst.)] x 10(-5) and B(eta' -> pi(+) pi(-) pi(0) pi(0)) = [1.82 +/- 0.35(stat.) +/- 0.18(syst.)] x 10(-4), which are consistent with theoretical predictions based on a combination of chiral perturbation theory and vector-meson dominance.
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| 7. |
- Ablikim, M., et al.
(författare)
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Observation of J/psi -> p(p)over-bara(0)(980) at BESIII
- 2014
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Ingår i: Physical Review D. - 1550-7998 .- 1550-2368. ; 90:5, s. 052009-
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Tidskriftsartikel (refereegranskat)abstract
- Using 2.25 x 10(8) J/psi events collected with the BESIII detector at the BEPCII storage rings, we observe for the first time the process J/psi -> p (p) over bara(0)(980) -> pi(0)eta with a significance of 6.5 sigma (3.2 sigma including systematic uncertainties). The product branching fraction of J/psi -> p (p) over bara(0)(980) -> p (p) over bara(0)pi(0)eta is measured to be (6.8 +/- 1.2 +/- 1.3) x 10(-5), where the first error is statistical and the second is systematic. This measurement provides information on the a(0) production near threshold coupling to p (p) over bar and improves the understanding of the dynamics of J/psi decays to four-body processes.
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| 8. |
- Ablikim, M., et al.
(författare)
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Precision measurement of the mass of the tau lepton
- 2014
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Ingår i: Physical Review D. - 1550-7998 .- 1550-2368. ; 90:1
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Tidskriftsartikel (refereegranskat)abstract
- An energy scan near the tau pair production threshold has been performed using the BESIII detector. About 24 pb(-1) of data, distributed over four scan points, were collected. This analysis is based on t pair decays to ee, e mu, eh, h, hh, e.,. and p. final states, where h denotes a charged p or K. The mass of the t lepton is measured from a maximum likelihood fit to the t pair production cross- section data to be m(tau) = 1776.91 +/- 0.12_0.10 - 0.13 _ MeV/c(2), which is currently the most precise value in a single measurement.
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| 9. |
- Ablikim, M., et al.
(författare)
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Search for eta(c)(2S)h(c) -> p(p)over-bar decays and measurements of the chi(cJ) -> p(p)over-bar branching fractions
- 2013
-
Ingår i: Physical Review D. - 1550-7998 .- 1550-2368. ; 88:11, s. 112001-
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Tidskriftsartikel (refereegranskat)abstract
- Using a sample of 1.06 x 10(8)psi(3686) events collected with the BESIII detector at BEPCII, the decays eta(c)(2S) -> p (p) over bar and h(c) -> p (p) over bar are searched for, where eta(c)(2S) and h(c) are reconstructed in the decay chains psi(3686) -> gamma eta(c)(2S), eta(c)(2S) -> p (p) over bar and psi(3686) -> pi(0)h(c), h(c) -> p (p) over bar, respectively. No significant signals are observed. The upper limits of the product branching fractions are determined to be B(psi(3686) -> gamma eta(c)(2S)) x B(eta(c)(2S) -> p (p) over bar) < 1.4 x 10(-6) and B(psi(3686) -> pi(0)h(c)) x B(h(c) -> p<(p)over bar>) < 1.3 x 10(-7) at the 90% C.L.. The branching fractions for chi(cJ) -> p<(p)over bar> (J = 0, 1, 2) are also measured to be (24.5 +/- 0.8 +/- 1.3, 8.6 +/- 0.5 +/- 0.5, 8.4 +/- 0.5 +/- 0.5) x 10(-5), which are the world's most precise measurements.
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| 10. |
- Ablikim, M., et al.
(författare)
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Search for the radiative transitions Psi(3770) -> gamma eta(c) and gamma eta(c) (2S)
- 2014
-
Ingår i: Physical Review D. - 1550-7998 .- 1550-2368. ; 89:11, s. 112005-
-
Tidskriftsartikel (refereegranskat)abstract
- By using a 2.92 fb-1 data sample taken at pffisffiffi 3.773 GeV with the BESIII detector operating at the BEPCII collider, we search for the radiative transitions.d3770c and cd2S through the hadronic decays cdcd2S. K0 SK p. No significant excess of signal events above background is observed. We set upper limits at a 90% confidence level for the product branching fractions to be Bdd3770cxBd.c. K0 SK k p < 1.6x10-5 and Bd.d3770cd2SxBd.cd2S. K0 SK p<5.6x10-6. Combining our result with world-average values of Bd.cd.cd2S. K0 SK p, we find the branching fractions Bd.d3770c< 6.8 x 10-4 and Bd.d3770cd2S< 2.0 x 10-3 at a 90% confidence level.
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| 11. |
- Ablikim, M., et al.
(författare)
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Search for the rare decays J/y -> D-s(-) rho(+) and J/psi -> <(D)over bar(0)<(K)over bar*(0)
- 2014
-
Ingår i: Physical Review D. - 1550-7998 .- 1550-2368. ; 89:7, s. 071101-
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Tidskriftsartikel (refereegranskat)abstract
- A search for the rare decays of J/psi -> D-S(-) rho(+) + c.c. and J/psi -> <(D)over bar(0)<(K)over bar*(0) + c.c. is performed with a data sample of 225.3-million J/psi events collected with the Beijing Spectrometer III detector. No evident signal is observed. Upper limits on the branching fractions are determined to be beta(J/psi -> D-S(-)rho(+) + c.c.) < 1.3 x 10(-5) and beta(J/psi -> <(D)over bar(0)<(K)over bar*(0) + c.c.) < 2.5 x 10(-6) at the 90% confidence level.
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| 12. |
- Ablikim, M., et al.
(författare)
-
Study of e(+)e(-) -> p(p)over-bar in the vicinity of psi(3770)
- 2014
-
Ingår i: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 735, s. 101-107
-
Tidskriftsartikel (refereegranskat)abstract
- Using 2917 pb(-1) of data accumulated at 3.773 GeV, 44.5 pb(-1) of data accumulated at 3.65 GeV and data accumulated during a psi(3770) line-shape scan with the BESIII detector, the reaction e(+)e(-) -> p (p) over bar is studied considering a possible interference between resonant and continuum amplitudes. The cross section of e(+)e(-) -> psi(3770) -> p (p) over bar, sigma(e(+)e(-)-> psi(3770) -> p (p) over bar), is found to have two solutions, determined to be (0.059(-0.020)(+0.070) +/- 0.012) pb with the phase angle phi = (255.8(-26.6)(+39.0) +/- 4.8). (< 0.166 pb at the 90% confidence level), or sigma(e(+)e(-) -> psi(3770) -> p<(p)over bar>) = (2.57(-0.13)(+0.12) +/- 0.12) pb with phi = (266.9(-6.3)(+6.1) +/- 0.9)degrees both of which agree with a destructive interference. Using the obtained cross section of psi(3770) -> p (p) over bar, the cross section of p (p) over bar -> psi(3770), which is useful information for the future PANDA experiment, is estimated to be either (9.8(-3.9)(+11.8)) nb (< 27.5 nb at 90% C.L.) or (425.6(-43.7)(+42.9)) nb. (C) 2014 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license.
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| 13. |
- Ablikim, M., et al.
(författare)
-
Study of e(+)e(-) -> p(p)over-bar pi(0) in the vicinity of the psi(3770)
- 2014
-
Ingår i: Physical Review D. - 1550-7998 .- 1550-2368. ; 90:3, s. 032007-
-
Tidskriftsartikel (refereegranskat)abstract
- The process e(+)e(-) -> p (p) over bar pi(0) has been studied by analyzing data collected at root s = 3.773 GeV, root s = 3.650 GeV, and during a psi(3770) line shape scan with the BESIII detector at the BEPCII collider. The Born cross section of p (p) over bar pi(0) in the vicinity of the psi(3770) is measured, and the Born cross section of psi(3770) -> p (p) over bar pi(0) is extracted considering interference between resonant and continuum production amplitudes. Two solutions with the same probability and a significance of 1.5 sigma are found. The solutions for the Born cross section of psi(3770) -> p (p) over bar pi(0) are 33.8 +/- 1.8 +/- 2.1 pb and 0.06(-0.04-0.01)(+0.10+0.01) pb (< 0.22 pb at a 90% confidence level). Using the estimated cross section and a constant decay amplitude approximation, the cross section sigma(p<(p)over bar> -> psi(3770)pi(0)) is calculated for the kinematic situation of the planned (p) over bar ANDA experiment. The maximum cross section corresponding to the two solutions is expected to be less than 0.79 nb at 90% confidence level and 122 +/- 10 nb at a center-of-mass energy of 5.26 GeV.
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| 14. |
- Ablikim, M., et al.
(författare)
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Observation of the decay psi(3686) -> Lambda(Sigma)over-bar(+/-) pi(-/+) + c.c
- 2013
-
Ingår i: Physical Review D. - 1550-7998 .- 1550-2368. ; 88:11, s. 112007-
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Tidskriftsartikel (refereegranskat)abstract
- Using a sample of 1:06 X 10(8) psi(3686) events collected with the BESIII detector, we present the first observation of the decays of psi(3686) -> Lambda(Sigma) over bar (+) pi(-) + c.c. and psi(3686) -> Lambda(Sigma) over bar (-) pi(+) + c.c. The branching fractions are measured to be B(psi(3686) -> Lambda(Sigma) over bar (+) pi(-) + c.c.) = (1.40 +/- 0.03 +/- 0.13) X 10(-4) and B(psi(3686) -> Lambda (Sigma) over bar (-) pi(+) + c.c.) = (1.54 +/- 0.04 +/- 0.13) X 10(-4) where the first errors are statistical and the second ones systematic.
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| 15. |
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| 16. |
- Ablikim, M., et al.
(författare)
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Measurements of (XcJ)-> K+K-K+K- decays
- 2006
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Ingår i: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 642:3, s. 197-202
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Tidskriftsartikel (refereegranskat)abstract
- Using 14M psi(2S) events taken with the BESII detector, chi(cJ) -> 2(K+K-) decays are studied. For the four-kaon final state, the branching fractions are B(chi(c0,1,2) ->.2(K+K-)) = (3.48 +/- 0.23 +/- 0.47) x 10(-3), (0.70 +/- 0.13 +/- 0.10) x 10(-3), and (2.17 +/- 0.20 +/- 0.31) x 10(-3). For the phi K+K- final state, the branching fractions, which are measured for the first time, are B(chi(c0,1,2) -> phi K+K-) = (1.03 +/- 0.22 +/- 0.15) x 10(-3), (0.46 +/- 0.16 +/- 0.06) x 10(-3), and (1.67 +/- 0.26 +/- 0.24) x 10(-4). For the phi phi final state, B(chi(c0,2) -> phi phi) = (0.94 +/- 0.21 +/- 0.13) x 10(-3) and (1.70 +/- 0.30 +/- 0.25) x 10(-3).
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| 17. |
- Ryu, Y. -H., et al.
(författare)
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OGLE-2016-BLG-1190Lb : The First Spitzer Bulge Planet Lies Near the Planet/Brown-dwarf Boundary
- 2018
-
Ingår i: Astronomical Journal. - : American Astronomical Society. - 0004-6256 .- 1538-3881. ; 155:1
-
Tidskriftsartikel (refereegranskat)abstract
- We report the discovery of OGLE-2016-BLG-1190Lb, which is likely to be the first Spitzer microlensing planet in the Galactic bulge/ bar, an assignation that can be confirmed by two epochs of high-resolution imaging of the combined source-lens baseline object. The planet's mass, M-p = 13.4 +/- 0.9 M-J, places it right at the deuteriumburning limit, i. e., the conventional boundary between planets and brown dwarfs. Its existence raises the question of whether such objects are really planets (formed within the disks of their hosts) or failed stars (lowmass objects formed by gas fragmentation). This question may ultimately be addressed by comparing disk and bulge/bar planets, which is a goal of the Spitzer microlens program. The host is a G dwarf, M-host = 0.89. +/- 0.07 M-circle dot, and the planet has a semimajor axis a similar to 2.0 au. We use Kepler K2 Campaign 9 microlensing data to break the lens-mass degeneracy that generically impacts parallax solutions from Earth-Spitzer observations alone, which is the first successful application of this approach. The microlensing data, derived primarily from near-continuous, ultradense survey observations from OGLE, MOA, and three KMTNet telescopes, contain more orbital information than for any previous microlensing planet, but not quite enough to accurately specify the full orbit. However, these data do permit the first rigorous test of microlensing orbital-motion measurements, which are typically derived from data taken over < 1% of an orbital period.
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| 18. |
- Udalski, A., et al.
(författare)
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OGLE-2017-BLG-1434Lb : Eighth q < 1 x 10(-4) Mass-Ratio Microlens Planet Confirms Turnover in Planet Mass-Ratio Function
- 2018
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Ingår i: Acta Astronomica. - 0001-5237. ; 68:1, s. 1-42
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Tidskriftsartikel (refereegranskat)abstract
- We report the discovery of a cold Super-Earth planet (m(p) = 4.4 +/- 0.5 M-circle plus) orbiting a low-mass (M = 0.23 +/- 0.03 M-circle dot) M dwarf at projected separation a(perpendicular to) l = 1.18 +/- 0.10 a.u., i.e., about 1.9 times the distance the snow line. The system is quite nearby for a microlensing planet, D-L = 0.86 +/- 0.09 kpc. Indeed, it was the large lens-source relative parallax pi(rel) = 1.0 mas (combined with the low mass M) that gave rise to the large, and thus well-measured, microlens parallax pi(E) proportional to (pi(rel)/M)(1)(/2) that enabled these precise measurements. OGLE-2017-BLG-1434Lb is the eighth microlensing planet with planet-host mass ratio q < 1 x 10(-4). We apply a new planet-detection sensitivity method, which is a variant of V/V-max, to seven of these eight planets to derive the mass-ratio function in this regime. We find dN/ d lnq proportional to q(P) , with p =1.05(-0.68)(+0.78), which confirms the turnover in the mass function found by Suzuki et al. relative to the power law of opposite sign n = -0.93 +/- 0.13 at higher mass ratios q greater than or similar to 2 x 10(-4). We combine our result with that of Suzuki et al. to obtain p = 0.73(-0.34)(+0.42.)
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| 19. |
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| 20. |
- Han, C., et al.
(författare)
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OGLE-2017-BLG-0329L : A Microlensing Binary Characterized with Dramatically Enhanced Precision Using Data from Space-based Observations
- 2018
-
Ingår i: Astrophysical Journal. - : American Astronomical Society. - 0004-637X .- 1538-4357. ; 859:2
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Tidskriftsartikel (refereegranskat)abstract
- Mass measurements of gravitational microlenses require one to determine the microlens parallax pE, but precise pE measurement, in many cases, is hampered due to the subtlety of the microlens-parallax signal combined with the difficulty of distinguishing the signal from those induced by other higher-order effects. In this work, we present the analysis of the binary-lens event OGLE-2017-BLG-0329, for which pi(E) is measured with a dramatically improved precision using additional data from space-based Spitzer observations. We find that while the parallax model based on the ground-based data cannot be distinguished from a zero-pi(E) model at the 2 sigma level, the addition of the Spitzer data enables us to identify two classes of solutions, each composed of a pair of solutions according to the well-known ecliptic degeneracy. It is found that the space-based data reduce the measurement uncertainties of the north and east components of the microlens-parallax vector pE by factors similar to 18 and similar to 4, respectively. With the measured microlens parallax combined with the angular Einstein radius measured from the resolved caustic crossings, we find that the lens is composed of a binary with component masses of either (M-1, M-2) similar to (1.1, 0.8) M-circle dot or similar to(0.4, 0.3) M-circle dot according to the two solution classes. The first solution is significantly favored but the second cannot be securely ruled out based on the microlensing data alone. However, the degeneracy can be resolved from adaptive optics observations taken similar to 10 years after the event.
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| 21. |
- Zhang, J. J., et al.
(författare)
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Epigenetic restoration of voltage-gated potassium channel Kv1.2 alleviates nerve injury-induced neuropathic pain
- 2021
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Ingår i: Journal of Neurochemistry. - : Wiley. - 0022-3042 .- 1471-4159. ; 156:3, s. 367-378
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Tidskriftsartikel (refereegranskat)abstract
- Voltage-gated potassium channels (Kv) are important regulators of neuronal excitability for its role of regulating resting membrane potential and repolarization. Recent studies show that Kv channels participate in neuropathic pain, but the detailed underlying mechanisms are far from being clear. In this study, we used siRNA, miR-137 agomir, and antagomir to regulate the expression of Kv1.2 in spinal cord and dorsal root ganglia (DRG) of naive and chronic constriction injury (CCI) rats. Kv currents and neuron excitability in DRG neurons were examined by patch-clamp whole-cell recording to verify the change in Kv1.2 function. The results showed that Kv1.2 was down-regulated in DRG and spinal dorsal horn (SDH) by CCI. Knockdown of Kv1.2 by intrathecally injectingKcna2siRNA induced significant mechanical and thermal hypersensitivity in naive rats. Concomitant with the down-regulation of Kv1.2 was an increase in the expression of the miR-137. The targeting and regulating of miR-137 onKcna2was verified by dual-luciferase reporter system and intrathecal injecting miR-137 agomir. Furthermore, rescuing the expression of Kv1.2 in CCI rats, achieved through inhibiting miR-137, restored the abnormal Kv currents and excitability in DRG neurons, and alleviated mechanical allodynia and thermal hyperalgesia. These results indicate that the miR-137-mediated Kv1.2 impairment is a crucial etiopathogenesis for the nerve injury-induced neuropathic pain and can be a novel potential therapeutic target for neuropathic pain management.
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| 22. |
- Boddaert, S., et al.
(författare)
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Fire safety of BIPV : International mapping of accredited and R&D facilities in the context of codes and standards 2023
- 2023
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The objective of Task 15 of the IEA Photovoltaic Power Systems Programme is to create an enabling framework to accelerate the penetration of BIPV products in the global market of renewables, resulting in an equal playing field for BIPV products, BAPV products and regular building envelope components, respecting mandatory issues, aesthetic issues, reliability issues, and financial issues.Subtask E of Task 15 is focused on pre-normative international research on BIPV characterisation methods and activity E.3 is dedicated to fire safety of BIPV modules and installations.
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| 23. |
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| 24. |
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| 25. |
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| 26. |
- Hirao, Yuki, et al.
(författare)
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OGLE-2017-BLG-0406 : Spitzer Microlens Parallax Reveals Saturn-mass Planet Orbiting M-dwarf Host in the Inner Galactic Disk
- 2020
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Ingår i: Astronomical Journal. - : American Astronomical Society. - 0004-6256 .- 1538-3881. ; 160:2
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Tidskriftsartikel (refereegranskat)abstract
- We report the discovery and analysis of the planetary microlensing event OGLE-2017-BLG-0406, which was observed both from the ground and by the Spitzer satellite in a solar orbit. At high magnification, the anomaly in the light curve was densely observed by ground-based-survey and follow-up groups, and it was found to be explained by a planetary lens with a planet/host mass ratio of q = 7.0 x 10(-4) from the light-curve modeling. The ground-only and Spitzer-only data each provide very strong one-dimensional (1D) constraints on the 2D microlens parallax vector pi(E). When combined, these yield a precise measurement of pi(E) and of the masses of the host M-host = 0.56 +/- 0.07 M-circle dot and planet M-planet = 0.41 +/- 0.05 M-Jup. The system lies at a distance D-L = 5.2 +/- 0.5 kpc from the Sun toward the Galactic bulge, and the host is more likely to be a disk population star according to the kinematics of the lens. The projected separation of the planet from the host is a(perpendicular to) = 3.5 +/- 0.3 au (i.e., just over twice the snow line). The Galactic-disk kinematics are established in part from a precise measurement of the source proper motion based on OGLE-IV data. By contrast, the Gaia proper-motion measurement of the source suffers from a catastrophic 10 sigma error.
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| 27. |
- Lim, H. D., et al.
(författare)
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Short-time proper orthogonal decomposition of time-resolved schlieren images for transient jet screech characterization
- 2020
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Ingår i: Aerospace Science and Technology. - : Elsevier BV. - 1270-9638 .- 1626-3219. ; 107
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Tidskriftsartikel (refereegranskat)abstract
- Short-time Proper Orthogonal Decomposition (POD) is proposed as an image-based technique to study the transient jet screech characteristics of moderately under-expanded supersonic jets emanating from a circular baseline and two bevelled nozzles. Time-resolved schlieren imaging of turbulent flow structures were performed with an ultrahigh-speed schlieren setup. Short-time POD was performed by systematically sampling image-series with a short time delay, performing PODs and applying spectral analyses on the first POD mode coefficients, and plotting the peak frequencies from the resulting PSDs into a peak frequency-occurrence count histogram. The results are in good agreement with the near-field noise spectra and wavelet transform analysis of the microphone measurements, which revealed intermittent jet screech occurrences at St=0.25 for both baseline and 30 degrees bevelled jets, while none was detected for the 60 degrees bevelled jet. In particular, the occurrence counts of the frequency bins is proposed as a suitable parameter to characterize the intermittent nature of jet screech, with the frequency bin revealing the jet screech frequency if present. The present study demonstrates the advantage of short-time POD analysis on time-resolved schlieren images over traditional image-based POD methods, which includes computational gains from parallelization, the ability to handle much larger datasets and revealing insights into a transient flow and noise phenomenon.
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| 28. |
- Mariani, Raffaello, et al.
(författare)
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A comparative study on the use of calibrated and rainbow schlieren techniques in axisymmetric supersonic jets
- 2019
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Ingår i: Flow Measurement and Instrumentation. - : Elsevier BV. - 0955-5986 .- 1873-6998. ; 66, s. 218-228
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Tidskriftsartikel (refereegranskat)abstract
- Detailed experimental comparisons had been conducted between calibrated and rainbow schlieren on perfectly-and under-expanded axisymmetric supersonic jets through a modified Z-type schlieren system. The techniques were implemented by using a weak lens in the field-of-view to provide calibration information for the extraction of quantitative density gradients from the experimental schlieren images. Sixth-order polynomial curve fits were obtained for both calibrated and rainbow schlieren respectively. The effects of light inhomogeneity caused by the mirrors and system diaphragm aperture had been evaluated for the colour images and results indicate that averaging the background hue is an acceptable approach for minimizing light variations with less than 2% experimental error. Density gradients as calculated via Abel transform have also been evaluated to validate the two different set-ups. Additionally, experimental results have been compared to validated numerical results and they show that calibrated schlieren is able to predict density gradients within 2% of the numerical results. This is significantly more superior to rainbow schlieren, where errors in the estimated density gradients are clOser to 20%. It is shown here that rainbow schlieren results are more adversely impacted by the system diaphragm aperture, especially for vertical light cut-off configuration. This is partly due to the loss of sensitivity of the schlieren system, as well as potential light diffusion caused by the filter.
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| 29. |
- Mariani, Raffaello, 1981-, et al.
(författare)
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A Preliminary Study On the Implementation of Rainbow Schlieren with a Single-Mirror System
- 2019
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Ingår i: Proc. of the 32nd International Symposium on Shock Waves. - Singapore : Research Publishing Services.
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Konferensbidrag (refereegranskat)abstract
- An experimental study has been conducted on the application of rainbowschlieren with a single-mirror schlieren system for the study of over- and moderatelyunder-expanded jets. The technique used a weak lens in the field-of-view to providecalibration information for the extraction of quantitative data. The calibration imagerequired post-processing procedures that take into account the double diffraction of thelight inherent to the schlieren system in use, resulting in an exploitable range of re-fraction angles of ±1.45e−3rad. Density gradients were calculated using Abel transformand compared to validated reference data. Results show an experimental uncertainty inthe predicted density gradients to be as low as ±2%, with an overall average of ±10%.These improvements over previous works can be attributed to the higher sensitivity ofthe present schlieren system.
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| 30. |
- Mariani, Raffaello, Assistant Prof. 1981-, et al.
(författare)
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On the application of non-standard rainbow schlieren technique upon supersonic jets
- 2020
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Ingår i: Journal of Visualization. - : Springer Nature. - 1343-8875 .- 1875-8975. ; 23:3, s. 383-393
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Tidskriftsartikel (refereegranskat)abstract
- Abstract: A quantitative rainbow schlieren study was conducted on an over-expanded jet at nozzle pressure ratio of 2.8, based on two different schlieren set-ups: the standard z-type and a single-mirror schlieren set-up. The technique used a single, weak focal-length lens placed in the field of view of the system to provide the calibration information required for the extraction of the quantitative data. In the case of the single-mirror set-up, the calibration image required further post-processing procedures to take into account the double refraction experienced by the light. Density gradients were calculated using Abel transform and compared to validated reference data. Results indicate that the single-mirror set-up is able to improve prediction of the density gradient field as compared to the standard z-type schlieren, due to its inherent property of higher sensitivity. The study has shown that the single-mirror set-up performs on average better than the standard z-type system, yielding an overall averaged error of ± 20%, with localized values as low as ± 5% where the shock cell structure is clearly defined, with respect to the validated reference data. At the same time, both systems perform poorly in regions where the flow structure displays poor image contrast. Graphic abstract: [Figure not available: see fulltext.].
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| 31. |
- Morita, M, et al.
(författare)
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Hepatic posttranscriptional network comprised of CCR4-NOT deadenylase and FGF21 maintains systemic metabolic homeostasis
- 2019
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Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : Proceedings of the National Academy of Sciences. - 1091-6490. ; 116:16, s. 7973-7981
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Tidskriftsartikel (refereegranskat)abstract
- Whole-body metabolic homeostasis is tightly controlled by hormone-like factors with systemic or paracrine effects that are derived from nonendocrine organs, including adipose tissue (adipokines) and liver (hepatokines). Fibroblast growth factor 21 (FGF21) is a hormone-like protein, which is emerging as a major regulator of whole-body metabolism and has therapeutic potential for treating metabolic syndrome. However, the mechanisms that control FGF21 levels are not fully understood. Herein, we demonstrate that FGF21 production in the liver is regulated via a posttranscriptional network consisting of the CCR4–NOT deadenylase complex and RNA-binding protein tristetraprolin (TTP). In response to nutrient uptake, CCR4–NOT cooperates with TTP to degrade AU-rich mRNAs that encode pivotal metabolic regulators, including FGF21. Disruption of CCR4–NOT activity in the liver, by deletion of the catalytic subunit CNOT6L, increases serum FGF21 levels, which ameliorates diet-induced metabolic disorders and enhances energy expenditure without disrupting bone homeostasis. Taken together, our study describes a hepatic CCR4–NOT/FGF21 axis as a hitherto unrecognized systemic regulator of metabolism and suggests that hepatic CCR4–NOT may serve as a target for devising therapeutic strategies in metabolic syndrome and related morbidities.
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| 32. |
- Wang, J. M., et al.
(författare)
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Melatonin receptor activation provides cerebral protection after traumatic brain injury by mitigating oxidative stress and inflammation via the Nrf2 signaling pathway
- 2019
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Ingår i: Free Radical Biology and Medicine. - : Elsevier BV. - 0891-5849. ; 131, s. 345-355
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Tidskriftsartikel (refereegranskat)abstract
- Traumatic brain injury (TBI) is a principal cause of death and disability worldwide. Melatonin, a hormone made by the pineal gland, is known to have anti-inflammatory and antioxidant properties. In this study, using a weight-drop model of TBI, we investigated the protective effects of ramelteon, a melatonin MT1/MT2 receptor agonist, and its underlying mechanisms of action. Administration of ramelteon (10 mg/kg) daily at 10:00 a.m. alleviated TBI-induced early brain damage on day 3 and long-term neurobehavioral deficits on day 28 in C57BL/6 mice. Ramelteon also increased the protein levels of interleukin (IL)-10, IL-4, superoxide dismutase (SOD), glutathione, and glutathione peroxidase and reduced the protein levels of IL-1 beta, tumor necrosis factor, and malondialdehyde in brain tissue and serum on days 1, 3, and 7 post-TBI. Similarly, ramelteon attenuated microglial and astrocyte activation in the perilesional cortex on day 3. Furthermore, ramelteon decreased Keap 1 expression, promoted nuclear factor erythroid 2-related factor 2 (Nrf2) nuclear accumulation, and increased levels of downstream proteins, including SOD-1, heme oxygenase-1, and NQO1 on day 3 post-TBI. However, in Nrf2 knockout mice with TBI, ramelteon did not decrease the lesion volume, neuronal degeneration, or myelin loss on day 3; nor did it mitigate depression-like behavior or most motor behavior deficits on day 28. Thus, timed ramelteon treatment appears to prevent inflammation and oxidative stress via the Nrf2-antioxidant response element pathway and might represent a potential chronotherapeutic strategy for treating TBI.
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| 33. |
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| 34. |
- Zang, ZL, et al.
(författare)
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Valproic acid exposure decreases neurogenic potential of outer radial glia in human brain organoids
- 2022
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Ingår i: Frontiers in molecular neuroscience. - : Frontiers Media SA. - 1662-5099. ; 15, s. 1023765-
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Tidskriftsartikel (refereegranskat)abstract
- Valproic acid (VPA) exposure during pregnancy leads to a higher risk of autism spectrum disorder (ASD) susceptibility in offspring. Human dorsal forebrain organoids were used to recapitulate course of cortical neurogenesis in the developing human brain. Combining morphological characterization with massive parallel RNA sequencing (RNA-seq) on organoids to analyze the pathogenic effects caused by VPA exposure and critical signaling pathway. We found that VPA exposure in organoids caused a reduction in the size and impairment in the proliferation and expansion of neural progenitor cells (NPCs) in a dose-dependent manner. VPA exposure typically decreased the production of outer radial glia-like cells (oRGs), a subtype of NPCs contributing to mammalian neocortical expansion and delayed their fate toward upper-layer neurons. Transcriptomics analysis revealed that VPA exposure influenced ASD risk gene expression in organoids, which markedly overlapped with irregulated genes in brains or organoids originating from ASD patients. We also identified that VPA-mediated Wnt/β-catenin signaling pathway activation is essential for sustaining cortical neurogenesis and oRGs output. Taken together, our study establishes the use of dorsal forebrain organoids as an effective platform for modeling VPA-induced teratogenic pathways involved in the cortical neurogenesis and oRGs output, which might contribute to ASD pathogenesis in the developing brain.
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